Method of and package for sterilized edible material

Abstract

A thin walled, easily crushable container with an integral or seamed-on bottom is filled with an edible material which requires sterilization. The empty container has one end attached or integral that may have a concave slope relative to the inside of the container. A liquified or solidified inert gas is then inserted into the container. The container is then sealed with a concave shaped end before the inert liquified or solidified gas has completely vaporized. The ends are such that they do not bulge under the pressure left after sterilization, which pressure is due to the pressurization effect of the inert gas and which pressure is enough to overcome the vacuum caused by the cooling of hot water vapor or steam above the edible material and gives the can the required rigidity. If one end is concave shaped and will invert or bulge at bacterial gas pressure but not at the gas pressure left after sterilization, then the other end does not necessarily have to be concave as long as it does not bulge at the pressure left after sterilization.

What is claimed is: 
     
       1. A pressurized sealed container containing sterilized edible material, which comprises: a thin wall sealed container containing edible material sterilized in a sterilization process and an inert gas under pressure, the walls of the container being maintained rigid by the pressure of the inert gas but being easily deformable in the absence of such pressure, the container having a top end and a bottom end with at least one end having a concave slope relative to the inside of the container, the at least one end being of a material and having a thickness and shape such that said at least one end of said sealed container will retain a substantially concave slope before, during and after said sterilization process but will become convex only if there is any additional gas pressure generated due to bacterial action in the pressurized sealed container.   
     
     
       2. The pressurized sealed container in accordance with claim 1, wherein the sterilization process is an autoclave sterilization process. 
     
     
       3. The pressurized sealed container in accordance with claim 1, wherein the sterilization process is an aseptic sterilization process. 
     
     
       4. The pressurized sealed container in accordance with claim 1, wherein the sterilization process is a radiation sterilization process. 
     
     
       5. The pressurized sealed container in accordance with claim 1, wherein the container is a beverage-type container. 
     
     
       6. The pressurized sealed container in accordance with claim 5, wherein the container is made of metal. 
     
     
       7. The pressurized sealed container in accordance with claim 6, wherein the at least one end includes at least one stiffening bead. 
     
     
       8. The pressurized sealed container in accordance with claim 7, wherein the at least one end is an easy-open end. 
     
     
       9. A method of packaging sterilizable edible material, comprising: a) inserting an edible material to be sterilized into a thin wall container having an opened and closed end, the closed end being sealed with a first closing member;   b) inserting a predetermined amount of an inert liquified or solidified gas into the container;   c) allowing the gas to vaporize;   d) before the gas has completely vaporized, sealing the open end of the container with a second closing member such that the pressure of the inert gas in the sealed container is sufficient to maintain the walls of the container rigid, which walls would otherwise be easily deformable in the absence of said inert gas; and   (e) sterilizing the edible material and the container such that a pressurized sealed container containing sterilized edible material is formed; and wherein at least one of the first and second closing members has a concave slope relative to the inside of the container and is of a material and has a thickness and shape such that the at least one end of said sealed container will retain a substantially concave slope before, during and after steps (d) and (e) but will become convex only if there is any additional gas pressure generated due to bacterial action in the pressurized, sealed container.     
     
     
       10. A method of packaging in accordance with claim 9, wherein step (e) results in a vacuum and the amount of inert gas is sufficient to generate a pressure sufficient to balance the vacuum and to provide rigidity to the container. 
     
     
       11. A method of packaging in accordance with claim 10, wherein step (e) comprises autoclave sterilization which includes heating and cooling the container. 
     
     
       12. A method of packaging in accordance with claim 11, wherein steam is added to the container before sealing the open end thereof. 
     
     
       13. A method of packaging in accordance with claim 10, wherein the inert gas is solid carbon dioxide. 
     
     
       14. A method of packaging in accordance with claim 10, wherein the container is a beverage type container. 
     
     
       15. A method of packaging in accordance with claim 14, wherein the container is made of metal. 
     
     
       16. A method of packaging in accordance with claim 16, wherein the end includes at least one stiffening bead. 
     
     
       17. A method in accordance with claim 16, wherein the at least one end is an easy-open end. 
     
     
       18. A method of packaging in accordance with claim 9, wherein step (e) comprises aseptic sterilization which includes sterilizing the edible material and the container prior to step (a) and sterilizing the second closing member prior to step (d). 
     
     
       19. A method of packaging in accordance with claim 9, wherein step (e) comprises radiation sterilization which includes subjecting the container after step (d) to radiation sufficient to sterilize the edible material and the container. 
     
     
       20. A method of packaging in accordance with claim 9, wherein the inert gas is liquified nitrogen. 
     
     
       21. A method of packaging in accordance with claim 9, wherein the inert gas is liquified carbon dioxide.